Orthopedic implant in the form of a plate to be fixed between two bone parts

ABSTRACT

The invention relates to a plate fixed between two bone parts by way of screws engaged in holes formed in the thickness of said plate. The plate comprises an angled member or rib which is inclined according to an angle of between about 30° and 60° in relation to the plane defined by the plate. The angled member or rib has a hole for engaging a screw and is located in the central part of the width, over a determined part of the length of the plate, so that the screw brings the two bone parts into a compressive position.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation of U.S. application Ser. No.14/041,706, filed Sep. 30, 2013, which is a continuation of U.S.application Ser. No. 12/918,071, filed on Oct. 29, 2010 and now U.S.Pat. No. 8,556,946, which is a national phase entry under 35 U.S.C. §371of International Application No. PCT/FR2009/051879, filed Oct. 2, 2009,published in French, which claims priority from French PatentApplication No. 0856694, filed Oct. 2, 2008, all of which areincorporated herein by reference in their entireties.

BACKGROUND OF THE INVENTION

The invention relates to the technical field of orthopedic implants.

More particularly, the invention relates to a plate for arthrodesis orosteosynthesis adapted to be fixed between two bone parts.

In a manner known to one having ordinary skill in the art, this type ofplate generally has holes for engaging screws, allowing arthrodesisbetween two bones or osteosynthesis between two bone fragments. This is,for example, the case for bones of the hand or foot, without howeverexcluding other applications, particularly in the field of the spine.Depending on the pathology to be treated, these plates can have ageneral rectilinear or other geometric shapes.

From this state of the art, one of the objects the invention proposes toattain is to improve, in a sure and efficient manner, compression in aprecise direction between the bone parts subjected to the plate.

To attain the given object to enhance the compression between the tworelative bone parts, according to the invention, the plate has aformation that orients at least one screw at an angle with respect to aplane defined by the plate, the angle being between about 30° and 60°.

According to an advantageous embodiment, the formation is a tab that isangled according to an angle between 30° and 60°, and having a hole forengaging the screw. The angled tab results from a cut out and adeformation of a portion of the plate.

In another embodiment, the formation is a hole angled at an anglebetween 30° and 60° for engaging the screw.

Considering the problem to be solved, the formation is located on adetermined portion of the length of the plate so that the screw ensuresthe compression of the two bone parts.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention is described hereinafter in more detail, with reference tothe attached drawings in which:

FIG. 1 is a perspective view of an embodiment of the plate;

FIG. 2 is a side view of the plate;

FIGS. 3 and 4 are perspective views showing the mounting of the platebetween two bone parts and their orientation by means of the plateaccording to the invention, the bone parts being shown schematically.

DETAILED DESCRIPTION

According to the invention, the plate 1 has at least one formation laadapted to enable the positioning of at least one screw 2, at an angle αof between 30° and 60° with respect to a plane of the plate (FIG. 2).

In one embodiment, the formation 1 a is an angled tab cut out anddeformed from the plate. For example, the deformation is made with acutting-punching operation. This angled tab has a hole 1 a 1 for screw2. The angled tab 1 a is positioned along the length of the plate sothat after the screw 2 is fitted to it, the screw ensures thecompression together of the two bone parts, as indicated below in thedescription.

In another embodiment, to allow for an angular orientation of the screw2 according to an angle between about 30° and 60°, the formation 1 a canbe formed as an angled hole. It must be noted that the tab 1 a enablesadaptation of the angle as a function of the pathology to be treated,given that it is possible to deform this tab at will. In other words,the angle can be adjusted over a few degrees directly by the surgeon inthe operating room, using an appropriate tool.

With reference to FIGS. 3 and 4 that show the positioning of the plate 1between two bone parts O1 and O2:

Once the osteotomies have been carried out, a template of the plate,which does not have a guide formation, enables the position of the tabto be determined.

After determining the position of the tab, the surgeon makes acorresponding recess with the appropriate rasp.

Once the plate having the tab has been positioned, the surgeon sets oneor two screws 3, on a side of the site of the osteosynthesis or thearthrodesis toward the tab. A temporary fastening pin can, possibly, bepositioned in a complementary lug.

The screw 2 is then engaged in the hole 1 a 1 of the tab 1 a to placethe fracture in compression.

Once the compression has been done, the surgeon can screw one or severalother additional fastening screws 3 and remove the temporary pin.

In a known manner, this plate 1 has smooth and/or threaded holes for thefastening screws 3 set in the bone parts O1 and O2 to engage in, asshown in FIGS. 3 and 4.

Similarly, the plate 1 can have at least one hole 1 c for a pin fortemporarily positioning the plate 1. Advantageously, the plate 1 canhave a guide 1 c for the insertion of a pin on the side of one of thebone parts O1 and another guide 1 d for the insertion of another pin onthe side of the other bone part O2.

Considering the effect of the desired compression, such as indicatedabove, the guide 1 c is a circular hole whose diameter correspondssubstantially to that of the pin, whereas the other guide 1 d can be anelongated slot.

These provisions thus enable the bone to slide under the plate 1 as thescrews are set, while ensuring compression along a precise direction,generally axially or parallel to the plate. The pins are of any knownand appropriate type, and perfectly known to one having ordinary skillin the art.

The plate 1 can have several shapes, so that the holes 1 a in particularcan be aligned or arrayed, all or in part, according to the corners of atriangle or of a quadrilateral. These provisions, in triangle or inquadrilateral, of the screws, improve the stability of the mounting.

It must be noted also that the plate 1, no matter its shape, can belongitudinally bent so as to adapt to the curvature of the bone,consequently enabling the screws to form an angle between them.

The advantages are readily apparent from the description.

1. An orthopedic implant in the form of a plate adapted to be fixedbetween two bone parts by screws engaged in throughgoing holes, whereinthe plate has a formation that is set at an angle between 30° and 60°with respect to a plane defined by the plate and having a hole forreceiving a screw, the formation being located in a transversely centralportion along the length of the plate such that the screw compressestogether the two bones parts.